Small particle polyacrylamide for soil conditioning

Abstract

A method of producing an aqueous solution of water-soluble polyacrylamide (PAM) with a concentration of at least about 5 grams per liter includes the steps of providing a monovalent or divalent cation salt solution, and preferably a calcium salt solution, and adding water-soluble PAM particles to the salt solution such that the PAM particles are essentially all dissolved within about 10 seconds. The PAM particles are characterized by a particle size that is about −100 mesh and consisting essentially of molecules having a molecular weight of at least about 15 million a.u. Preferably, the small PAM particles are produced by a mill that produces bulk quantities of small dry, flowable PAM particles from larger commercial grade particles. Small PAM particles produced in such a mill are essentially all soluble in plain water within about 10 seconds. After solution, the polymer concentrate can be diluted with water to make stock solutions of the polymer for some purposes. For other purposes the concentrate can be injected directly into irrigation systems. Effectiveness of the water-soluble polyacrylamide as a soil conditioner is considerably increased by co-use with a calcium salt, gypsum, fertilizer salts, or a combination of these salts, in addition to the increased ease of making solutions.

Dependencies are inferred from the claim text.